1. Field of the Invention
The present invention relates to an active radio tag for use in entering and leaving management, presence management, and the like, and a security management system and a security management method that use the active radio tag.
2. Description of the Related Art
A radio tag is a contactless medium which has an ID (identification number) unique to the tag stored in its built-in memory and performs communication by radio with a receiver, and is generally called an RFID (Radio Frequency Identification) tag. Radio tags come in two types: passive and active. A passive radio tag does not contain therein an energy source (battery) and performs communication by driving an internal circuit based on electromagnetic energy obtained from a receiver within a predetermined area. On the other hand, an active radio tag contains therein an energy source (battery) and performs communication without the need of electromagnetic energy from a receiver.
In an active radio tag, a tag ID is automatically transmitted regardless of areas and thus the active radio tag is mainly used for presence management for persons or items, and the like. In addition, by encrypting a tag ID, an active radio tag can also be used for applications intended to restrict access, e.g., management of entering and leaving the room, management of using equipment, and the like. On the other hand, in a passive radio tag, its usable-areas are limited and thus the passive radio tag is mainly used for management of entering and leaving the room, management of using equipment, and the like. For example, a contactless IC card for use in management of entering and leaving the room is a kind of passive radio tag. For storage media for access restriction, in addition to a contactless IC card, a contact IC card and a magnetic card are also used.
As such, since there are two types of storage media having different purposes of use, a combined operation can be considered such as, for example, using an active radio tag for presence management for persons within premises and access management for specific location and equipment and using a card for other access management. In this case, a user needs to have two types of storage media; however, in terms of security, it is desirable that a single ID be provided to a single person. In addition, these storage media should essentially be possessed by the same single person. However, in the present circumstances, since a radio tag and a card can be operated separately, if only the radio tag is handed over to and used by another person, an illegal action can occur, such as the target of presence management becoming another person or another person using the radio tag and accessing specific location and equipment; accordingly, there is a security problem.
Japanese Patent Application Laid-Open No. 8-97777 describes a portable communication apparatus including a main body case in which an IC card having stored therein ID data unique to an owner can be placed and operation means and communication means which are provided to the main body case, in which when the operation means is operated the ID data stored in the IC card placed in the main body case is transmitted through the communication means. However, a technique disclosed in Japanese Patent Application Laid-Open No. 8-97777 is to enable transmission, by radio, of information stored in an IC card without processing the IC card itself and thus the target of operation is only an IC card and the technique is not about the combined use of a radio tag and an IC card. Therefore, with the technique disclosed in Japanese Patent Application Laid-Open No. 8-97777, the above-described problem which arises when different storage media are operated in combination cannot be solved.